RESUMO
gem-Difluoroalkenes are widely used building blocks in fluorine chemistry. Herein, a metal-free photocatalytic amination and heteroarylation method of gem-difluoroalkenes with heteroaryl carboxylic acid oxime esters as substrates is reported. This environmentally benign reaction proceeds via radical-radical cross-coupling in energy-transfer-mediated photocatalysis and can be used in the rapid construction of heteroaryl difluoroethylamine scaffolds and late-stage modification of complex pharmaceutical structures.
RESUMO
The formation of biofilm is one of the important factors for bacteria to develop drug-resistant. A series of halogenated-pyrroles or pyrazoles containing thiazole groups as antibacterial agents were designed and synthesized to target biofilms. Among them, compound 8c showed antibacterial activity against various Gram-positive bacteria, particularly against vancomycin-resistant Enterococcus faecalis (MIC ≤0.125 µg/mL). Additionally, this compound significantly inhibited biofilm formation of Staphylococcus aureus and Pseudomonas aeruginosa at sub-MIC doses. Furthermore, compound 8c exhibited significantly lower mammalian cell toxicity compared to pyrrolomycin C and its hepatic microsomal metabolic stability in various species was also evaluated. Further experiment on the infection model of Galleria mellonella proved that the compound was effective in vivo.
RESUMO
Sulfonamides are important structures in pharmaceuticals, agrochemicals, and organocatalysts, yet the rapid and benign synthesis of these compounds is still a great challenge. Herein we report a photoinduced method for synthesizing sulfonamides from (hetero)aryl carboxylic acid oxime esters. This reaction proceeds via one-pot cascade radical-radical cross-coupling by energy-transfer-mediated photocatalysis. A wide substrate scope including (hetero)aryl substrates and late-stage modification of pharmaceutical molecular entities reveal its generality.
RESUMO
A simple and efficient synthetic approach to 2-amino-9H-chromeno[2,3-d]thiazol-9-ones via copper-promoted cascade reactions was developed. The reaction employed easily available 2-amino-3-iodochromones and amines as substrates and the targeting tricyclic compounds could be obtained with moderate to good yields. Even more important, several synthesized compounds exhibited potent anti-inflammatory activities, which suggested that this protocol may provide valuable hits for drug development in the future.